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Test Code WAS Seq WAS Gene Sequencing

Important Note

Test availability is limited to Seattle Children’s Hospital and University of Washington patients.

Clinical System Name

WAS Gene Sequencing




Wiskott-Aldrich syndrome (WAS) is an X-linked disease characterized by thrombocytopenia with small platelets, eczema, cellular and humoral immunodeficiency, autoimmune disease, and malignancy. WAS is caused by mutations in the Wiskott-Aldrich Syndrome Protein (WASP). WASP is an intracellular protein expressed exclusively in hematopoietic cells. It functions to enhance actin polymerization and branching allowing cells to rearrange their actin cytoskeleton. Cytoskeletal rearrangement is vital for a number of key functions in immune cells such as endocytosis, exocytosis, chemotaxis, and formation of the immunologic synapse.

Sample Requirements

Specimen: Whole blood

Container(s): Dark Green/Sodium Heparin, Lavender/EDTA

Preferred Vol: 5 mL

Minimum Vol: 3 mL


Specimen: Extracted DNA

Minimum: 5µg

Note: DNA concentration minimum 100 µg/mL; 260/280 ratio 1.70-2.00


Specimen: Cultured cells

Acceptable:  Fibroblasts, amniocytes, chorionic villus sampling (CVS)

Container(s): T-25 flasks

Preferred Vol: 2 flasks


Note: Direct testing on amniocentesis and chorionic villus sampling (CVS) is not performed; samples must be cultured by external lab.

Processing Instructions

Reject due to: Clotting

Spin: No

Aliquot: No

Temp: Room temperature

Storage location: Molecular Genetics Box in CPA refrigerator #2


Off-site collection: Refrigerate blood samples until ready to ship. Transport all sample types at room temperature via overnight shipping



Specimen Type Temperature Time
Cultured cells Room temp 3 days
Whole blood, extracted DNA Room temp 3-5 days
Whole blood, extracted DNA Refrigerated 7 days
Extracted DNA Frozen 5 years


Note: Whole blood samples > 7days may be submitted to be assessed by our lab for acceptability for testing.


STAT Performed TAT
Contact lab Monday - Friday 8-10 weeks


Performing Laboratory

Seattle Children's Laboratory


Department:  Molecular Genetics Lab


Lab Client Services: 206-987-2617,

Lab Genetic Counselor:

Reference Range

Interpretive report will be provided


Method: The 12 exons of the WAS gene, including exon/intron boundaries, are amplified from genomic DNA by PCR and sequenced bidirectionally using dye-terminator chemistry.


Limitations: Mutations in the promoter region, large deletions, large duplications, or rare recombinant mutations may not be detected by this method.

CPT Codes

81406x1     (updated 2/16/2015 by sstasi) 

Special Instructions

Links to:  Immunology Diagnostic Laboratory


IDL Requisition

Clinical Utility

To determine if there is occurrence of variation in patient WASP sequence compared to wild type.